Children exposed to high levels of interparental conflict are at disproportionately high risk for experiencing a wide array of psychological problems, including internalizing symptoms, externalizing problems, social impairments, and academic difficulties. Consequently, the burden experienced by children from high conflict homes and the resulting psychological, health, and economic costs to U.S. society are extensive. Children's emotional responses to conflict are regarded as pivotal mechanisms in understanding the risk associated with exposure to interparental discord and conflict. Thus, in accordance with the Funding Opportunity Announcement PA-07-083 Basic and Translational Research in Emotion, this study proposes to test a pattern-based reformulation of EST that is rooted in an ethological and evolutionary framework (EST-R; Davies & Sturge-Apple, 2007; Davies & Woitach, 2008). Toward the overarching objective of examining the utility of the novel EST-R framework, this application seeks to address the following specific aims: (1) Identify the nature of the interrelationships among the five profiles, the patterns of subjective reactivity to conflict underlying each profile, and stability and change in the profiles over time; (2) Identify the interparental, family, and child characteristics that serve as correlates and precursors in distinguishing between the different reactivity profiles; (3) Distinguish the common and distinctive neurobiological and neurocognitive underpinnings of children's behavioral profiles of reactivity to conflict; (4) Delineate the mental and physical health trajectories of the EST- R profiles, including testing the incremental power of the specific profiles to predict specific trajectories of children's adjustment after taking into account prevailing measurement approaches; and (5) Contribute to intervention initiatives aimed at addressing children's coping and adaptation to interparental conflict by delineating possible points of intervention associated with particular patterns of children's responding. To accomplish these aims, the project will follow a sample of 250 mothers, fathers, and their four year-old children over three annual measurement occasions. The multi-method, multi-informant, and multi-level measurement battery combined with powerful, sophisticated latent and pattern-based quantitative approaches will generate authoritative tests of the novel, theoretically guided research questions and hypotheses. Consequently, the study has the potential to significantly advance knowledge on family and developmental processes underlying children's trajectories of health and inform prevention and intervention initiatives to alleviate the impact of risky family environments on the development of trauma related psychopathology towards reducing the burden of mental illness in children.